Conventionally, a drive assist control technique, which assists driving of a subject vehicle by controlling a light image projected on a road surface of a travelling road in front of the subject vehicle, is known as a technique for securing safety.
For example, in the drive assist control technique disclosed in Patent Literature 1, the informative light image, which indicates information to be displayed to an occupant in the subject vehicle, is projected on the road surface. As a result, the occupant of the subject vehicle can drive with safety secured based on the information indicated by the informative light image. A person around the subject vehicle can avoid danger with safety secured based on the information indicated by the informative light image.